Image:
Male Quang's Tree Frog

Notes

In most frog species, males call to attract females with a rather repetitive call- the familiar "croak, croak, croak". Quang's Tree Frog, on the other hand, has what is known as a hyperextended vocal repertoire. In other words, it doesn't just repeat the same call over and over, but has a number of types of calls. In fact, no two calls recorded were exactly the same, with each frog mixing clicks, whistles and chirps in no apparent order. It is certainly one of the most variable frog calls known, and sounds quite like a bird song.